1. Field of the Invention
This invention relates to a transverse force rod bearing having a transverse force rod, a transverse force rod bearing sleeve and at least one bearing cage supporting the bearing sleeve, as well as a front plate disposed on the sides of a joint gap to be bridged.
2. Description of Prior Art
Conventional transverse force rods are connecting and pressure distributing elements for two structural concrete elements extending in the same general plane, which are separated from each other by a joint. A transverse force rod bearing is known from European Patent Publication EP-A-0 119 652, which consists of a transverse force rod, a transverse force rod bearing and a bearing cage supporting the bearing sleeve. Furthermore a front plate in the form of four brackets, arranged in a cross shape, is disposed on a side of a joint gap to be bridged. This front plate is merely used for fixing the transverse force rod bearing sleeve on a form while producing the concrete plate in which the bearing sleeve is encased. The bearing cage consists of a number of closed loops made of reinforcement steel wires with a bent hook projecting into the interior, in which the sleeve is seated. Thus the loops are located in planes which are parallel with a direction of extension of the joint.
Another conventional transverse force rod bearing is disclosed in European Patent Publication EP-A-0 193 494. In this embodiment the support of the transverse force rod bearing sleeve is independent of the bearing cage. Thus a mounting shoe is fastened at a front form, into which a front plate, which is fixedly connected with the transverse force rod sleeve, can be pushed. A height-adjustable support bar is provided at a closed end of the transverse force rod bearing sleeve, which assures correct support of the bearing sleeve when it is encased in concrete. The front plate only has a support function during the setting in concrete. The independent bearing cage has appropriate steel rings, in which both the sleeve and the transverse force rod are supported.
A multitude of other conventional transverse force rod bearings are known, in addition to the above-described transverse force rod bearing systems. One of the most important problems in connection with the transverse force rod bearing is that, although high-performance steel is available so that the occurring forces can be transmitted without problems, the pressure limit for concrete is considerably exceeded in an area of the transverse force rod or the transverse force rod bearing sleeve. Even though this problem can be resolved by increasing the number of transverse force rods in the running direction of the expansion joint, this results in considerably increased cost.
Furthermore, a conventional system of the Pfluger and Partners Company is known, wherein respectively two transverse force rods arc disposed vertically above each other. In tests, the danger of exceeding a pressure limit for concrete by this has been reduced by arranging anchor rods, disposed vertically with respect to the running direction of the transverse force rods, in a groove extending transversely to the running direction of two transverse force rod sleeves and connecting them. However, the surface increase achieved by this is relatively small, so that the mentioned problem is only slightly alleviated.
A system of the Aschwanden Company is furthermore known, in which the respective transverse force rod is held on one side in a cup, into which high-quality concrete is poured. Although the permissible pressure limit of concrete is exceeded inside the cup, force transfer takes place to the cup, and the concrete extending above the cup is relieved to the extent that here the permissible pressure limit is no longer exceeded. However, the seating problem of the transverse force rod or the transverse force rod sleeve during installation is considerably increased by this arrangement.